It kinda appears this is possibly another case of CC expecting players to play with injury and toughen up (as evidenced with what Critta said he told Fox).
Whilst that's good in theory, if a player is out there useless with only one functioning arm (or making out he only has use of one arm) how is that helping the team by giving the opposition the added benefit of targetting his side of the field.
I think that's the issue here....that Fox was "appearing" to us, media, Parra that he was out there and a liability in defence and attack.